(a) Field of the Invention
The present invention relates to an improved structure of a smoke generator, more particularly to a heating vaporization device of the smoke generator to quickly heat and achieve complete vaporization of a chemical solution.
(b) Description of the Prior Art
In stage performance, smoke can create good visual effects. Smoke effects generally fall into two forms. In the first form, the smoke pervades the air. In the second form, the smoke is low and hangs above the floor of the stage. In general, dry ice is used to create the second form of smoke effect. However, dry ice is expensive.
The first form of smoke effect is indispensable in stage performances. With reference to FIG. 1, a conventional smoke generator generally includes a pump A that is communicates with a container D for storing a chemical solution C via a duct B. The pump A pumps chemical solution C to a heating tank E where the solution C is heated and vaporized to form smoke and mist. The smoke thus generated passes through a nozzle provided on the heating tank E to pervade the air and create the desired visual effect. It can therefore be seen that the function of the heating and vaporization device of the conventional smoke generator is mainly to ensure complete vaporization of the chemical solution and avoid ejection of smoke in the form of droplets that may scald people around or wet the floor, which is dangerous.
The heating tank E shown in FIG. 1 is the subject of R.O.C. Utility Model Pat. No. 119093 to the inventor of the present invention. The heating tank E includes a base E1 internally provided with a base hole E2 and a heating chamber E3. A screw rod E4 is disposed in the base hole E2. A solution duct E5 transports the solution C supplied via the pump A into the base hole E2 so that the solution C travels along the screw rod E4 towards a smoke ejecting device E6 at a front end of the base hole E2. A heating device E7 is provided inside the heating chamber E3 to heat the base hole E2 above. The high temperature thus generated causes the solution C to become vaporized, and the smoke is ejected by the smoke ejecting device E6. The above-described heating and vaporization device can achieve complete vaporization of the solution C. But the heating device E7 must be pre-heated prior to use to a temperature sufficient to vaporize the solution C in order pump the solution C to the base hole E2 for vaporization using the pump A. Such an indirect method of heating is not very satisfactory. Besides, since use of the heating tube is power-consuming, alternating currents are utilized. In outdoor occasions where alternating currents are unavailable, a heating and vaporization device as such cannot be used.